a compositor mode for editing images inside blender

What you're looking for is the ability to have the Shader Editor take an output from the Compositor as an input. That's something I can get behind. I'm not sure the way you're suggesting to go about it is the best way, though.

+1 As Texture Node editor needs to be moved somewhere. This is the right direction to make compositor as a proper texture node editor.

Glad it has come to Right click. I was about to make one

Reason:

From Procedural Texture creation pipeline:

1. Get all image filter ops in an inexpensive buffer this way. ie: Filters, Blur etc from compositor.

Not possible with texture editor. And crucial in texture creation.

2. Utilizing mask nodes.

3. As it's a 2D texture, this can be used directly for Texture Painting, Brush making and last but not least for Triplanner Mapping.

From Compositor Pipeline:

1. It is ESSENTIAL to have procedural textures in compositor environment to create effects like smoke, displace etc.
2. Making loop pipeline from 2D to 3D. Example: Green screen extract in compositor and exporting it in a 3d card/plane with Shader editor. demo: youtu.be/0OdFo8evnYs

TODO:

1. Port all texture nodes from texture node editor into Compositor. Currently done by the "Texture node" in compositor.
2. Updating node terms properly currently present in texture node editor. (some are arbitrarily defined)

3. Making a node to transfer the output of the texture/composited output into Shader Editor and Texture panel. Currently done by saving image instead. ___________________

Demo:

This is a demo why it is important and can give versatile possibility. Currently we are doing it with auto reload addon: youtu.be/qcb8uoaDy4w __________

Blender do have a Texture Node Editor, but from what i see it is very limited. as it only support , these texture data (Also one more for displacement texture) I'm actually not sure what is the reason the textures have to be 4 separated data, why can't they all using one generic image texture data? Sorry for bit out of topic for the last part. But in my opinion having a good and "generic image texture" processor are a good idea

Blender's compositor is very powerful already but there are basic things that are still lacking which include this kind of functionality. As far as I know creating a flat text in the compositor is not even possible, only in the video sequencer.

There is a lot of attempt to make substance designer's like texture edition in blender today but they all use the shader editor which is not the right tool to do that kind of stuff. Too slow (because of recompute the entire graph for each sample), too heavy (due to a lot of tricks to simulate trivial image processing nodes like blurs or contour detection), this could be done easily with a real non destructive texture editor like in this proposal. This could authorize caching strategy and parallelized computation of image.

To have a usable workflow the procedural texture node need to have multiple output and custom internal parameters exposition. We will need some new node too like generators, GLSL or shadertoy customisable nodes.

It could be interesting to be able to load the render output of another scene as texture input (with the associated AOV to post process it and use the result directly as a texture) for complex pattern design for example, something substance designer haven't ;-)

I often use compositing software to make non destructive texture workflow and it work pretty well. If i could have this directly in blender it would be amazing.

You can use Krita o Gimp